Electric transformer-furnace.



0. FRIGK.

3120mm TRANSFORMER FURNAGE.

APPLICATION FILED MAR. Z, 1904.

Patented Apr. 6, 1909.

a Invenmr.

Witnesses.

'of the King of Sweden, and

closed n'mgnetic cor-c, one limb OTTO liltIOK, OF SALTSJGBADEN, SWEDEN.

I ELEETREIJ SFGEthfIER-EYJRNACE;

Specification of Letters Patent.

?e,teritecl itpril o, tees- Applieatiou tiled March 2, 1904. Serial No. 196,132.

To all whom it may concern;

Be it known that 3. Genre Furor sul'iject nt of Saitsgtorlen, Sweden, have urventeri an Electric Transformer urnsce, of which the following u specification, reference being had to the occoniponyiug draw n forming it part lie-reel.

The lDVCJitiOIl I'Bid tes to on improved electric transformer furnace in which the moss to he heated is contained in an annular,

. .1 1 Gal t surrounded by the ir and 11;; the said primary Winding and the other iimos of which do not close y surround the primary winding, but are at such a. distance from the saidwinding that a, free space is left between the iron and the prinurry Winding.

In the accompmiyiug drawing 1 have shown diagrzutuui:iticully one embodiment of I my; invention, Figure l lacing transverse section through the furnace and e plan View thereof.

l ieferrin to the drawing, 1 designates the masonry of the furnace provit ed on its upper surface with a circular hearth .2, in which the material to he tree toil is placed.

The furnace works, as rule, with lnoiten material, for instance, steel, which is filled in from a suitable melting furnace, though the furnace may also he charged with unfused material. In every case the material to he treated forms a closetlelectric circuit in the hearth, its is well known from other transformer furnaces. y

8 designates a primary coil which is to he connected in well luiowil manner to an eiectriceitcrnating current erieretor, which supplies the furnacewith to necessary electric energ The coil 3 faces a. horizontal side of the hearth end is suitably pieced shove the letter, cs shown in the drowing.

'4. designstes'c rectangular iron core one liinh 4" of which is surrounded by the heart .2 the primary coil, other lin c a l, 4 and 4 of the core do not closely 1- elude the primary and secondary circuits of the transformer furnace, us is usu in dinaryprunsforniers, but are at, such a. die

tance frointhein that the leakage fish s when.

the furnace is working do not in tn-essential degree pass through the iron. As shown in the drawing the lir nhs i and 4 are not in OOH'LiLC'iJ with the primary Winding, hut'hsve s. free space between them and the soirl winding, and alsohetween the limbs 4 and 4 and the secondary circuit is a space is greater than the spscc between the primary and secondary circuits;

in Fig. 1 have shown by dottedv the limits of the main parts of the holds when the furnace i s Working. The sue main port of the leakage field of the primary Winrling may he supp sod to occupy the space sues equal around the primary coii to sl first to the shortest d stance between coil one the center ofthe cross section of the second cry circuit. By the dotted lines a. f), c d;

l hsveindiceteri the cross section or scidrprimary leaksve field. In the same manner the main part of the leakage field of the secondary circuit may be supposed to occupy the space around the secondary circuit to a, distance equal to the shortest distcnee from tlic said circuit to the center of the cross-section of the primary Winding. By the dotted line 8, f, g, ft, I have indicated the cross section of the said secondary leakage field. As Will be seen from the drawing, the limbs 4914 and 4' of the iron core are at such a distance from the primary and secondary circuits that the leakage fields limited by the lines a, b, c, d, and e, f, g, h, respectively do not in on essential degree pass through the said limbs.

'An'essentisl feature of my invention shove. described lies in the possibility of designing the cross-sectional form of the primary Wind-= ing Without interfering-with the diameter of the secondary Ineinoer, while at the some time lron is avoided. 1D. the leakage fields.

By the combination of e primary winding facing a horizontal sole of the hearth and a.

magnetic core of the form above described}.

am able to uses primary coil of end a e osed magnetic 'core, one limb (if which siso thst'fumsces ere known 1;; whieh are ran emesl 'cs as Bevel but endmy circuits he one above b ofez-her, and

used iron sores, which are at a ooinpzirtai-iv'vy greatdlstenee frets the prmmry-and se e l" 1 My en'euits, and i do not regard. such an V'hat claim iw- 1. An eieesrieind "'01.: furnace COKlPl'iu" isg a masonry base with an amuflmr earth for the material to be treated forming the seeondaw circuit Off/11G furnaue,e pz'imm'y windin facing a horizontsi side of the hearth,

is surrmmdedlgy the heag'th and by she said primary winclmg and the oth en. hmbs of which are vie sum distance from. the said winding; that free iron and said Windin 2. An electric induction furnace eompris ing; a; masonry base havin an. annular hearth m1" is m be tresbed & primary 33mm: the hearth and facing the :e, and closed n'mgl'zetic core in inductive inlion m the hmufl'l and primary Winding, H1111) of which core is surrounded by the \earth and. prinmry Winding and the other he eof are beyond the essential parks 7 .he & age of the primary windings and seconds! 7 circuit 01,,

pace is lefs befiween the g nod by the hem-11.

in testimony whereof I have signed my name to this specification, in the presence of twee bsajfiibing witnesses.

Witnesses:

FREDRZK L. ENQUIST,, A. HELJESTRAND. 

